Systems and methods for endovascular aneurysm treatment

ABSTRACT

Embodiments provide methods and systems for treating aneurysms using filling structures filled with a curable medium. An embodiment of a method comprises positioning at least one double-walled filling structure across the aneurysm and filling the structure(s) with a filling medium so that an outer wall conforms to the inside of the aneurysm and an inner wall forms a generally tubular lumen to provide for blood flow. The lumen is supported with a balloon or other expandable device while and/or after filling. The pressure within the structure and/or in the space between an external wall of the structure and the aneurysm wall is monitored and a flow of the medium into the structure is controlled responsive to the pressure. The pressure can also be used to determine a filling endpoint. The medium is hardened while the lumen remains supported by the balloon. The balloon is then removed after the medium hardens.

CROSS-REFERENCES TO RELATED APPLICATIONS

The present application is a Continuation of U.S. application Ser. No.14/537,749 filed Nov. 10, 2014, which is a Continuation of U.S.application Ser. No. 12/684,074 filed Jul. 7, 2010 now U.S. Pat. No.8,906,084, which is a Divisional of U.S. application Ser. No. 11/482,503filed on Jul. 7, 2006 now U.S. Pat. No. 7,666,220, which claims thebenefit of priority of U.S. Provisional Application Ser. No. 60/696,818filed on Jul. 7, 2005, and U.S. Provisional Application Ser. No.60/696,817 filed on Jul. 7, 2005; the full disclosures of which areincorporated herein by reference in their entirety for all purposes.

The present application is also related to U.S. patent application Ser.No. 11/187,471 filed on Jul. 22, 2005, the full disclosure of which isincorporated herein by reference.

BACKGROUND OF THE INVENTION Field of the Invention

Embodiments of the present invention relate generally to medicalapparatuses and methods for treatment. More particularly, embodiments ofthe present invention relate to expandable prostheses and methods fortreating abdominal and other aneurysms.

Aneurysms are enlargements or “bulges” in blood vessels which are oftenprone to rupture and which therefore present a serious risk to thepatient. Aneurysms may occur in any blood vessel but are of particularconcern when they occur in the cerebral vasculature or the patient'saorta.

Embodiments of the present invention are particularly concerned withaneurysms occurring in the aorta, particularly those referred to asaortic aneurysms. Abdominal aortic aneurysms (AAA's) are classifiedbased on their location within the aorta as well as their shape andcomplexity. Aneurysms which are found below the renal arteries arereferred to as infrarenal abdominal aortic aneurysms. Suprarenalabdominal aortic aneurysms occur above the renal arteries, whilethoracic aortic aneurysms (TAA's) occur in the ascending, transverse, ordescending part of the upper aorta.

Infrarenal aneurysms are the most common, representing about seventypercent (70%) of all aortic aneurysms. Suprarenal aneurysms are lesscommon, representing about 20% of the aortic aneurysms. Thoracic aorticaneurysms are the least common and often the most difficult to treat.Most or all present endovascular systems are also too large (above 12French) for percutaneous introduction.

The most common form of aneurysm is “fusiform,” wherein the enlargementextends about the entire aortic circumference. Less commonly, theaneurysms may be characterized by a bulge on one side of the bloodvessel attached at a narrow neck. Thoracic aortic aneurysms are oftendissecting aneurysms caused by hemorrhagic separation in the aorticwall, usually within the medial layer. The most common treatment foreach of these types and forms of aneurysm is open surgical repair. Opensurgical repair is quite successful in patients who are otherwisereasonably healthy and free from significant co-morbidities. Such opensurgical procedures are problematic, however, since access to theabdominal and thoracic aortas is difficult to obtain and because theaorta must be clamped off, placing significant strain on the patient'sheart.

Over the past decade, endoluminal grafts have come into widespread usefor the treatment of aortic aneurysm in patients who cannot undergo opensurgical procedures. In general, endoluminal repairs access the aneurysm“endoluminally” through either or both iliac arteries in the groin. Thegrafts, which typically have fabric or membrane tubes supported andattached by various stent structures are then implanted, typicallyrequiring several pieces or modules to be assembled in situ. Successfulendoluminal procedures have a much shorter recovery period than opensurgical procedures.

Present endoluminal aortic aneurysm repairs, however, suffer from anumber of limitations. A significant number of endoluminal repairpatients experience leakage at the proximal juncture (attachment pointclosest to the heart) within two years of the initial repair procedure.While such leaks can often be fixed by further endoluminal procedures,the need to have such follow-up treatments significantly increases costand is certainly undesirable for the patient. A less common but moreserious problem has been graft migration. In instances where the graftmigrates or slips from its intended position, open surgical repair isrequired. This is a particular problem since the patients receiving theendoluminal grafts are those who are not considered good candidates foropen surgery. Further shortcomings of the present endoluminal graftsystems relate to both deployment and configuration. The multiplecomponent systems require additional time for introducing each piece andeven more time for assembling the pieces in situ. Such techniques arenot only more time consuming, they are also more technicallychallenging, increasing the risk of failure. Current devices are alsounsuitable for treating many geometrically complex aneurysms,particularly infrarenal aneurysms with little space between the renalarteries and the upper end of the aneurysm, referred to as short-neck orno-neck aneurysms. Aneurysms having torturous geometries are alsodifficult to treat.

For these reasons, it would desirable to provide improved methods,systems, and prostheses for the endoluminal treatment of aorticaneurysms. Such improved methods, systems, and treatments shouldpreferably provide implanted prostheses which result in minimal or noendoleaks, resist migration, are relatively easy to deploy, have a lowintroduction profile (preferably below 12 French), and can treat most orall aneurysmal configurations, including short-neck and no-neckaneurysms as well as those with highly irregular and asymmetricgeometries. At least some of these objectives will be met by theinventions described hereinafter.

Description of the Background Art

Grafts and endografts having Tillable components are described in U.S.Pat. Nos. 4,641,653; 5,530,528; 5,665,117; and 5,769,882; U.S. PatentPublications 2004/0016997; and PCT Publications WO 00/51522 and WO01/66038.

BRIEF SUMMARY OF THE INVENTION

Embodiments of the present invention provides methods, systems, andprostheses for the endoluminal treatment of aneurysms, particularlyaortic aneurysms including both abdominal aortic aneurysms (AAA's) andthoracic aortic aneurysms (TAA's). A prosthesis can comprisedouble-walled filling structures which are pre-shaped and otherwiseadapted to substantially fill the enlarged volume of an aneurysm,particularly a fusiform aneurysm, leaving a lumen in place for bloodflow. Many embodiments utilize pressure monitoring at the aneurysm siteto control the filling of the filling structure and determine endpointsfor filling.

Embodiments of the double-walled filling structures will thus usuallyhave a generally toroidal structure with an outer wall, an inner wall, apotential space or volume between the outer and inner walls to be filledwith a filling medium, and a generally tubular lumen inside of the innerwall which provides the blood flow lumen after the prosthesis has beendeployed. Other shapes are also contemplated. The shape of the fillingstructure will be preferably adapted to conform to the aneurysm beingtreated. In some instances, the filling structure can be shaped for theaneurysmal geometry of a particular patient using imaging andcomputer-aided design and fabrication techniques. In other instances, afamily or collection of filling structures will be developed havingdifferent geometries and sizes so that a treating physician may select aspecific filling structure to treat a particular patient based on thesize and geometry of that patient's aneurysm. In all instances, theouter wall of the filling structure will conform or be conformable tothe inner surface of the aneurysm being treated. The inner wall of thestructure will be aligned with lumens of the blood vessels on eitherside of the prosthesis after the prosthesis has been deployed.

The filling structures of the prosthesis will usually be formed from anon-compliant material, such as parylene, Dacron, PET, PTFE, a compliantmaterial, such as silicone, polyurethane, latex, or combinationsthereof. Usually, it will be preferred to form at least the outer wallpartially or entirely from a non-compliant material to enhanceconformance of the outer wall to the inner surface of the aneurysm. Thisis particularly true when the aneurysm has been individually designedand/or sized for the patient being treated.

The walls of the filling structures may consist of a single layer or maycomprise multiple layers which are laminated or otherwise formedtogether. Different layers may comprise different materials, includingboth compliant and/or non-compliant materials. The structure walls mayalso be reinforced in various ways, including braid reinforcementlayers, filament reinforcement layers, and the like. In some instances,it would be possible to include self-expanding scaffolds within thefilling structures so that the structures could be initially deliveredand be allowed to self-expand at the treatment site, thus obviating theneed for an expansion delivery catheter as described as the preferredembodiment below.

Preferred delivery protocols will utilize delivery catheters having aballoon or other expandable support for carrying the filling structure.When using balloons, the balloons will preferably be substantially orentirely compliant, although non-compliant and combinationcompliant/non-compliant balloons may also find use. The balloon or othermechanical expansion components of the delivery catheter will initiallybe disposed within the inner tubular lumen of the filling structure,with the filling structure generally being collapsed into a low width orlow profile configuration over the expansion element. The deliverycatheter may then be introduced intraluminally, typically into the iliacartery and upwardly to the region within the aorta to be treated. Thedelivery catheter will also include one or more lumens, tubes, or othercomponents or structures for delivering the filling medium in a fluidform to an internal filling cavity of the filling structure. Thus, thedelivery catheter can be used to both initially place and locate thefilling structure of the prosthesis at the aneurysmal site. Once at theaneurysmal site, the internal tubular lumen of the structure can beexpanded using the balloon or other expandable element on the deliverycatheter. The filling structure itself will be filled and expanded bydelivering the filling medium via the catheter into the internal volumeof the filling structure. Both expansion and filling operations may beperformed simultaneously, or can be performed in either order, i.e., thefilling structure may be filled first with the delivery catheter balloonbeing expanded second, or vice versa. The filling structure(s) and/ordelivery balloons may have radio-opaque markers to facilitate placementand/or pressure sensors for monitoring filling and inflation pressuresduring deployment.

In preferred embodiments of the invention, pressure monitoring can beperformed at various stages of the aneurysm repair procedure to helpcontrol the filling process of the filling structure. The monitoring ofpressures serves to reduce the risk of dissection or damage to theaneurysm from over-pressurization and also can be used to determine anendpoint for filling. Monitoring can be done before during or afterfilling and hardening of the filling structure with filling medium.Specific pressures which can be monitored include the pressure withinthe internal space of the filling structure as well as the pressure inthe space between the external walls of the filling structure and theinner wall of the aneurysm. A composite measurement can also be madecombining pressures such as those measured within the interior space ofthe filling structure, together with that measured in the space betweenthe external walls of the structure and the aneurysm wall or other spaceat the aneurysm site and an external delivery pressure used by a fluiddelivery device, such as a pump, to deliver the filling medium. Controldecisions can be made using any one of these pressure or a combinationthereof.

Pressures can be measured using a number of pressure sensing means knownin the art including pressure sensors placed on the interior or exteriorof the filling structure as well as a pressure monitoring catheter,guidewire or other pressure sensing member placed at the aneurysm sitebetween the structure and the aneurysm wall. The pressure sensing meanscan in turn be coupled to a pressure monitoring means such as a gauge,electronic pressure monitor, computer or the like. A signal from thepressure sensor(s) can be inputted to a pressure monitoring and controldevice such as computer which can utilize the signal in algorithm tocontrol the flow rate and pressure of a pump or other coupled the fluiddelivery device used to deliver the filling medium. Pressures can bemonitored so as to stay below a selected threshold pressure which mayresult in an increased likelihood of dissection of the aneurysm wall dueto pressure forces exerted on the wall from the pressure exerted by thefilling structure during filling. The threshold pressure can bedetermined based on the size and shape of the particular aneurysm, thepatient blood pressure, the wall thickness of the aneurysm and otherdimensional, mechanical and morphological characteristics of theaneurysm site. In particular embodiments the Law of Laplace can beemployed to determine the forces which will be exerted on the arterialwall for a given filling pressure. The pressures can also be monitoredto stay below a threshold rate or pressure increase.

In many embodiments, the monitored pressures can be used to control oneor both of the flow rate and filling pressure of filling medium into thefilling structure. Control can be effected manually using a syringe orautomatically using a metered pump or other fluid delivery device whichis coupled to a controlling computer or other control system. Forexample, flow rates can be decreased or stopped when the pressure or arate of pressure increase reaches a threshold value either in theinterior or exterior of the filling structure. Also pressure monitoringcan be used to determine an endpoint for the delivery of the fillingmedium. An endpoint decision can be determined based on reaching aparticular pressure value for the interior and/or exterior space of thefilling structure. Endpoint can also be determined by combining ameasured pressure (d) together with a delivered volume of medium, andimaging observations on the size and shape of the expanded fillingstructure. For example, an endpoint can be reached when a factorialvalue of pressure and volume has been reached. In this way, an endpointdecision can be made using a multi-parameter analysis to provide a morecomprehensive determination for knowing on the one hand when the fillingstructure is adequately filled and on other assuring that it is notover-pressurized. Also in related embodiments, pressure monitoring canbe used to titrate the total delivery of medium into the fillingstructure.

In preferred aspects of the present invention, the filling structurewill be filled with a fluid (prior to hardening as described hereinbelow) at a pressure which is lower than that of the expansion forceprovided by the delivery catheter, typically the filling pressure of theexpandable balloon. Typically, the filling structure will be filled withfilling medium at a pressure from 80 mm of Hg to 1000 mm of Hg,preferably from 200 mm of Hg to 600 mm of Hg, while the delivery balloonis inflated to a pressure in the range from 100 mm of Hg to 5000 mm ofHg, preferably from 400 mm of Hg to 1000 mm of Hg. These pressures aregage pressures, i.e., pressures measured relative to atmosphericpressure. As is descried herein in many embodiments, the pressure withinor external the double-walled structure will be monitored and comparedto a maximum or other value of the patient's blood pressure. In suchcases, the filling pressure can be titrated so as to stay below athreshold pressure relative to the patient's blood pressure, for example90%, 100%, 110%, 150%, 200%, 250 or 300% of the patient's maximum bloodpressure (or other pressure value). In this way, real time pressuremonitoring can be used to reduce the likelihood of vessel dissectioncaused by over-pressurization of the aneurysm from the pressure exertedby the filling structure during filling.

As described thus far, embodiments of the invention contemplate deliveryof a single prosthesis and filling structure to an aneurysm. Delivery ofa single filling structure will be particularly suitable for aneurysmswhich are remote from a vessel bifurcation so that both ends of thefilling structure are in communication with only a single blood vessellumen. In the case of aneurysms located adjacent a vessel bifurcation,such as infrarenal abdominal aortic aneurysms, it will often bepreferable to utilize two such filling structures introduced in agenerally adjacent, parallel fashion within the aneurysmal volume. Inthe specific case of the infrarenal aneurysms, each prosthesis willusually be delivered separately, one through each of the two iliacarteries. After locating the filling structures of the prosthesis withinthe aneurysmal space, they can be filled simultaneously or sequentiallyto fill and occupy the entire aneurysmal volume, leaving a pair of bloodflow lumens. Pressure monitoring can be done before, during or after thefilling of one or both filling structures. Threshold pressure can alsobe adjusted accordingly (e.g., up or down) for the use of two fillingstructures. Also, adjustments can be made for the effect of filling onefilling structure on the measured pressure in the interior space of theother.

Suitable materials for the fluid filling medium (also described hereinas filling material) will be fluid initially to permit delivery throughthe delivery catheter and will be curable or otherwise hardenable sothat, once in place, the filling structure can be given a final shapewhich will remain after the delivery catheter is removed. The Tillablematerials will usually be curable polymers which, after curing, willhave a fixed shape with a shore hardness typically in the range from 10durometer to 140 durometer. The polymers may be delivered as liquids,gels, foams, slurries, or the like. In some instances, the polymers maybe epoxies or other curable two-part systems. In other instances, thepolymer may comprise a single material which when exposed to thevascular environment within the filling structure changes state overtime, typically from zero to ten minutes. In still other instances, thefilling medium need not be hardenable/curable but may remain liquid andcan have rheological properties configured to mimic blood or nativetissue. Such mediums can include various silicone and collagen solutionsknown in the art.

In a preferred aspect of the present invention, after curing, thefilling material will have a specific gravity, typically in the rangefrom 0.1 to 5, more typically from 0.8 to 1.2 which is generally thesame as blood or thrombus. The filling material may also include bulkingand other agents to modify density, viscosity, mechanicalcharacteristics or the like, including microspheres, fibers, powders,gasses, radiopaque materials, drugs, and the like. Exemplary fillingmaterials include polyurethanes, collagen, polyethylene glycols,microspheres, and the like.

Preferably, the filling structures of the prosthesis will require noadditional sealing or anchoring means for holding them in place withinthe aneurysm. In some instances, however, it may be desirable to employsuch additional sealing or anchoring mechanisms, such as stents,scaffolds, hooks, barbs, sealing cuffs, and the like. For sealing cuffsor stents which extend proximately of infrarenal prosthesis, it may bedesirable to provide openings or ports to allow the anchoring or sealingdevices to extend over the renal ostia while penetrating blood flow intothe renal arteries. The sealing or anchoring devices will typically beattached to and/or overlap with the filling structure of the prosthesisand will provide for a smooth transition from the aortic and/or iliaclumens into the tubular lumens provided by the deployed fillingstructures.

The filling structures may be modified in a variety of other ways withinthe scope of the present invention. For example, the external surfacesof the filling structures may be partially or entirely modified toenhance placement within the aneurysmal space, typically by promotingtissue ingrowth or mechanically interlocking with the inner surface ofthe aneurysm. Such surface modifications include surface roughening,surface stippling, surface flocking, fibers disposed over the surface,foam layers disposed over the surface, rings, and the like. It is alsopossible to provide biologically active substances over all or a portionof the external surface of the filling structure, such as thrombogenicsubstances, tissue growth promotants, biological adhesives, and thelike. It would further be possible to provide synthetic adhesives, suchas polyacrylamides, over the surface to enhance adherence. Also thesurface of the structure can be coated with one or more antibiotics toreduce the risk of post-implant infection.

In some instances, it will be desirable to modify all or a portion ofthe internal surface of the filling cavity of the filling structure.Such surface modifications may comprise surface roughening, rings,stipples, flocking, foam layers, fibers, adhesives, and the like. Thepurpose of such surface modification will usually be to enhance thefilling and bonding to the filling material, and to control the minimumwall thickness when the structure is filled particularly after thefilling material has been cured. In particular instances, in locationsof the filling structure which will be pressed together when thestructure is deployed, thus potentially excluding filling material, itwill be desirable if the surfaces of the filling structure can adheredirectly to each other.

In view of the above general descriptions of the present invention, thefollowing specific embodiments may be better understood. In a firstspecific embodiment, methods for treating an aneurysm comprisepositioning at least one double-walled filling structure across theaneurysm. By “across” the aneurysms, it is meant generally that thefilling structure will extend axially from one anatomical location,which has been identified by imaging or otherwise as the beginning ofthe aneurysm to a space-part location (or locations in the case ofbifurcated aneurysm) where it has been established that the aneurysmends. After positioning, the at least one filling structure is filledwith a fluid filling medium so that an outer wall of the structureconforms to the inside of the aneurysm and an inner wall of thestructure forms a generally tubular lumen to provide for blood flowafter the filling structure has been deployed. The tubular lumen willpreferably be supported by a support structure, typically a balloon ormechanically expansible element, while the filling structure is beingfilled, after the filling structure has been filled, or during bothperiods. The pressure exerted by the medium within or external thefilling structure can be monitored using a pressure sensing means suchas a pressure sensor positioned on the interior or exterior of thefilling structure. The pressure sensors can include various solid stateand MEMS-based sensors known in the art and can be configured to providepressure monitoring both during and after the filling procedure. Thepressure sensing means can also comprise a pressure monitoring catheter,guidewire or other pressure sensing member positioned at the aneurysmsite between the filling structure and the aneurysm wall. The pressuresensing member is desirably configured to be advanceble to the aneurysmsite from the point of arterial or venous access. It can have a pressuresensing lumen for fluid communication with a pressures sensing device,or it can have one or more pressure sensors positioned at it distal tip.The pressure sensing member can be configured to also be advanced intothe interior of the filling structure from a lumen in the deliverycatheter. In particular embodiments, two or more pressure sensingmembers can be used and positioned at different locations in or aroundthe aneurysm site to provide for differential pressure measurements.

The monitored pressure(s) can be used to control the flow rate offilling medium into filling structure and the filling pressure exertedby a syringe pump or other fluid delivery device. It can be also used todetermine an endpoint for filling of the filling structure. Filling canbe stopped or deceased when the monitored pressure exceeds a particularthreshold. The threshold can be established by comparison to ameasurement of the patient's blood pressure such as their maximumsystolic pressure. For example, filling can be slowed or stopped when amonitored pressure is in the range of 100 to 140% of the maximum bloodpressure with a specific embodiment of 110%. Also, similar to pressuremonitoring, the volume of delivered filling medium can be monitored andused to control the filling medium flow rate as well as endpoint eitherindependently or in combination with pressure measurement.

In various embodiments, filling can also be controlled by means of avalve coupled to the filling structure either directly or to a fillingtube coupled to filling structure. In one embodiment, the valve can beconfigured as a mechanical pressure relief valve to open and relievepressure from an interior of the structure when a threshold pressure hasbeen reached. In another embodiment the valve can be an electronicallycontrolled valve which either opens to relieve pressure within thefilling structure when the threshold pressure is reached or closes toprevent the influx of additional filling medium. In the former case, thevalve can be coupled to an exterior wall of the filling structure and inthe latter case it can be coupled to a filling tube or other fillingmember used to fill the filling structure. The valve can be controlledresponsive to a pressure signal directly or indirectly from the pressuresensing means, such as an electronic signal from a solid state pressuresensor.

After the filling structure has been filled, the filling material ormedium is hardened while the tubular lumen remains supported so as tomake a formed tubular lumen. Supporting the tubular lumen duringhardening assures that the formed lumen will have a desired geometry,will properly align with adjacent vascular lumens, and that the tubularlumen being formed remains aligned with the native aortic and/or iliacartery lumens after the prosthesis has been fully implanted. Preferably,the support will be provided by a balloon which extends proximally(upstream) and distally(downstream) out of the filling structure wherethe balloon may slightly “over-expand” in order to assure the desiredsmooth transition and conformance of the tubular lumen provided by thefilling structure with the native vessel lumens. In particularembodiments, the balloon can have a dog bone or similar shape such thatthe proximal and distal portions of the balloon are flared outwards orotherwise have a larger diameter than the central portion of theballoon. The ends of the inflated balloon extend at least partially outof the filling structure. This configuration serves to shape the lumenof the cured filling structure such that the proximal and distal ends ofthe formed lumen flare out relative to the central portion. This shapeserves to provide a smooth transition in diameter from the native vesselto the formed lumen and in particular minimizes the surface of the areaof the formed lumen that is normal to the direction of blood flowthrough artery. This later configuration serves to minimize an amount ofsheer stress on the formed and adjacent native lumens as well as reducean amount of retrograde flow and turbulence in vessel regions within andadjacent the prosthesis. These fluid dynamic factors serve to reduce thelikelihood of the formation of stenosis in the region of the prosthetic.

After hardening, the support will be removed, leaving the fillingstructure in place. In some cases, a drain device will be left in placeat the aneurysm site external to the filling structure to provide forthe post implant draining of blood or other fluids located in the spacebetween the aneurysm wall and the filled filling structure as discussedbelow. A porous portion of the device can be attached to an externalsurface of the filling structure to serve as a fluid inlet and anotherportion such as a drain tube may be positioned within the new or nativearterial lumen to serve as a fluid outlet. Desirably, the tube portiononly slightly extends into the native lumen and is positioned closely tothe lumen wall to minimize contact areas with flowing blood. The tubeportion can also be configured to be detachable by means of a guidewire,catheter or other minimally invasive method. This allows the physicianto remove the tube portion at a selected time period post implant (e.g.,two weeks) at which time it is no longer needed. The porous portion caninclude a plurality of apertures, can be wrapped helically or otherwisearound the perimeter of the filling structure to provide for multiplepoints of fluid entry. Desirably the drain device is constructed fromnon-thrombogenic biomaterials such as expanded PTFE so as to maintainpatentcy of the drain. It can also be constructed from re-absorbablebiomaterials known in the art which provide a drain function for aselected time period before being reabsorbed by the body. In someinstances, however, prior to hardening, it will be desirable to confirmproper placement of the filling structure. This can be done usingimaging techniques or otherwise testing for patency and continuity.

In some cases, it may be desirable to first fill the filling structurewith saline or other non-hardenable substance to make sure that thegeometry and size of the filling structure are appropriate for theparticular aneurysm. The fit of the filling structure within theaneurysm can be checked by imaging methods and the volume of saline canbe adjusted accordingly to produce a desired fit. For example thephysician can check to see if the filling structure has filled in theentire aneurysm space or if there any gaps remaining. This can befacilitated by the use of contrast agents added to the saline or othernon-hardenable filling solution. The volume of saline or other fluidwhich produces the desired fit can then be noted. After testing, thesaline may be removed and replaced with an equal or substantially equalvolume of hardenable filler and the remainder of the procedure followedas described above and herein. In use, these and related embodimentsprovide the physician with a means for improving and assuring the fit ofthe prosthesis at the aneurysm site before committing to the procedure.This results in improved clinical outcomes and reduced incidence ofmorbidity and mortality due to an improperly fit prosthesis.

Various embodiments of the invention also provide means and methods fordraining of blood (and other fluids) located between the exterior wallsof the filling structure and the inner walls of the aneurysm. Suchmethods reduce the pressure exerted on the aneurysms walls during thefilling procedure and provide for the draining of blood or other fluidswhich remain after the completion of the procedure. Several differentapproaches may be employed. In one approach, the support balloon orother mechanical support member are shaped so as to not form a seal withthe artery wall (when expanded) and thus allow blood to flow around theballoon/expansion device at desirably both the proximal and distal endsof the device. This allows any blood located between the filling deviceand aneurysm wall to readily flow out or be squeegeed out from theaneurysms site as the filling structure is expanded. In specificembodiments the balloon can have a multi-lobed cross sectional profilewhich allows blood to flow in the valleys between the lobes while peaksof the lobes provide support to maintain the tubular shape of the innerlumen of the filling member. In one embodiment, the balloon can have athree lobe structure. In other embodiments, the balloon support membercan comprise a multi-balloon member, for example, a three balloon memberthat allows for blood flow in the spaces between the balloons. In otherembodiments, an expandable shape memory stent can be used that allowsfor blood flow through the stent. In another, expandable basket-likestructures can be used. The expandable basket-like structures have aseries of spring memory splines or other spring member to hold the lumenopen, but still allows blood flow around and through the splines. Thestent or basket can have a deployed and non-deployed state. The stent orbasket can be deployed either through the application of tension orcompression which can be applied, for example, by the delivery catheteror guide wire. Other structures having spring memory materials which canbe mechanically engaged to a deployed state to support the inner lumencan also be used. These and related embodiments not only provide for theoutflow of blood located between the aneurysm wall and the fillingstructure but also for the normal flow of blood through the entirelength of the aneurysm site so as to maintain adequate perfusion oforgans and tissue downstream from the aneurysm site. Such perfusion canalso be achieved or supplemented by the use of a perfusion lumen andproximal and distal apertures in the delivery catheter which allowsblood to flow through the delivery catheter when the balloon is inflatedduring filling of the filling structure. In other embodiments allowingperfusion, the filling structure can comprise a continuously coiledstructure that has an open central lumen for blood flow which does notneed support during filling, or a series of inner tube like structuresthat are joined and also do not need to be supported during filling tomaintain patentcy of the central lumen.

In another approach for draining blood from the aneurysm site, a draindevice can be positioned on or nearby the exterior outer wall of thefilling structure. The drain can be configured to be removed after thecompletion of the filling procedure or left in place to provide for postimplant draining of the aneurysm site as is discussed below. The drainwill typically have a porous inflow portion and a tube outflow portion.The porous portion allows for the inflow of blood from an aneurysm site.The tube portion extends downstream or upstream from aneurysm site intothe native vessel lumen and provides for the outflow of blood. The tubeportion can be configured to extend a selectable length into the nativelumen. Preferably for post implant draining, the tube portion isconfigured to only slightly extend into the lumen of the native vesseland is configured to be located close to the lumen wall (e.g., severalmillimeters) to minimize contact area with flowing blood. It can becoupled to a catheter as discussed below.

The porous portion can include a plurality of apertures which allows forthe inflow of blood from multiple locations and also provides redundancyshould one or more of the apertures become blocked with thrombus orother matter. The porous portion can be helically or otherwise wrappedaround all or a portion of the perimeter of the filling structureexterior. Helically wrapping allows for the inflow of blood frommultiple locations around the filling structure and thus serves toproduce more uniform draining of blood or other fluid. In particularembodiments, the porous portion can also comprise a plurality of armswhich are longitudinally or otherwise distributed around the perimeterof the filling structure. The porous portion can be attached to thefilling structure with an adhesive or sonic weld or held in place bytension.

In many embodiments, the drain device is configured to provide a passivedraining function based from the pressure exerted by blood or otherfluid constrained between the filling structure and the inner walls ofthe filling aneurysm. In other embodiments, the drain can be configuredto be coupled to a vacuum so as to provide active draining by a vacuumforce. Vacuum application to remove blood can be done at any selectedtime during the repair procedure, including during or after filling ofthe filling structure. In some embodiments, blood can be withdrawnconcurrently to the injection of filling medium into the fillingstructure so as to control the pressure exerted by the filling medium onthe aneurysm wall. In particular embodiments, a substantially equalvolume of blood can be withdrawn from the aneurysm site as the volume ofmedium is injected into the filling structure. The withdrawal andinjection can be done simultaneously or near simultaneously andsubstantially at the same rate using concurrent injection and withdrawalmeans known in the art. Pressures can be monitored continuously duringthis operation and the withdrawal rate and/or injection rate can beadjusted accordingly to maintain pressure below a threshold or other setpoint.

Vacuum application can be achieved by coupling the tube or end portionof the drain to a dedicated lumen of the delivery catheter which is inturn connected to a vacuum source. Alternatively, the drain device canbe attached to a separate catheter for providing a dedicated source ofvacuum pressure. This latter configuration also provides a means forplacement and removal of the drain device independent from positioningof the delivery catheter.

In still other approaches, a drain function can be provided by means ofa needle which is inserted into the aneurysm site by a laparoscopicapproach or other method. A vacuum can then be pulled on the needleusing a syringe or other vacuum source. In a related approach, drainingcan be done using a pressure sensing member such as catheter or guidewire discussed herein which is appropriately positioned in the aneurysmsite. The pressure sensing member can provide for both passive drainingor active draining through the application of vacuum pressure to thepressure monitoring lumen of the catheter or guide wire. The lumendimension can be sized to provide for both pressure monitoring andblood/fluid removal functions. The pressure sensing member can also beused to supplement the draining function of a primary draining device aswell as reach particular locations between the aneurysm wall and fillingstructure that require additional draining or are otherwise inaccessibleto the primary drain device. This function can be achieved byconfiguring the pressure sensing member to be steerable using variouscatheter/guidewire fabrication techniques known in the art.

In a second specific embodiment of the present invention, abdominalaortic aneurysms and other bifurcated aneurysms are treated bypositioning first and second double-walled filling structures within theaneurysmal volume. The first and second double-walled filling structuresare positioned across the aneurysm, as defined above, extending from theaorta beneath the renal arteries to each of the iliac arteries,respectively. The first fluid filling structure is filled with a fluidfilling material, the second filling structure is also filled with afluid material, and the outer walls of each filling structure willconform to the inside surface of the aneurysm as well as to each other,thus providing a pair of tubular lumens for blood flow from the aorta toeach of the iliac arteries. Preferably, the tubular lumens of each ofthe first and second filling structures are supported while they arebeing filled or after they have been filled. Still further preferably,the tubular lumens will remain supported while the filling material ishardened, thus assuring that the transitions to the tubular lumens tothe native vessel lumens remain properly aligned and conformed.

In a third specific embodiment of the present invention, systems fortreating aneurysms comprise at least one double-walled filling structureand at least one delivery catheter having an expandable supportpositionable within a tubular lumen of the filling structure. Thesystems will usually further comprise a suitable hardenable or curablefluid filling medium. The particular characteristics of the fillingstructure and delivery balloon have been described above in connectionwith the methods of the present invention.

In a still further specific embodiment of the present invention, asystem for treating abdominal aortic aneurysms comprises a firstdouble-walled filling structure and a second double-walled fillingstructure. The first and second filling structures are adapted to befilled with a hardenable filling medium while they lie adjacent to eachother within the aneurysm. The systems further comprise first and seconddelivery catheters which can be utilized for aligning each of the firstand second filling structures properly with the right and left iliacsand the infrarenal aorta as they are being deployed, filled, andhardened.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A illustrates a single prosthesis system comprising a fillingstructure mounted over a delivery catheter.

FIG. 1B illustrates a single prosthesis system including a pressuremonitoring system for monitoring pressure during an aneurysm repairprocedure using a fillable prosthetic implant.

FIGS. 1C-E illustrate use of a pressure monitoring system during ananeurysm repair procedure using an fillable prosthetic implant.

FIG. 2 is a cross-sectional view of the filling structure of FIG. 1Aillustrating various surface modifications and a filling valve.

FIGS. 3A-3C illustrate alternative wall structures for the fillingstructure.

FIG. 4 illustrates the anatomy of an infrarenal abdominal aorticaneurysm.

FIGS. 5A-5D illustrate use of the prosthesis system of FIG. 1 fortreating the infrarenal abdominal aortic aneurysm.

FIG. 6 illustrates a system in accordance with the principles of thepresent invention comprising a pair of prosthesis for delivery to aninfrarenal abdominal aortic aneurysm, where each prosthesis comprises afilling structure mounted on a delivery catheter.

FIGS. 7A-7F illustrate use of the prosthesis system of FIG. 6 fortreating an infrarenal abdominal aortic aneurysm.

FIGS. 8A-8D illustrate use and placement of a drain device withembodiments of the prosthesis system.

FIGS. 9A-9F illustrate different embodiments of a drain device for usewith embodiments of the prosthesis system. FIG. 9A shows a porousportion of a drain device positioned in vessel space US, FIG. 9B shows adrain device with a porous portion positioned in space US coupled to avacuum source for active draining, FIG. 9C shows a drain device having ahelically wrapped porous portion, FIG. 9D shows a drain device having aplurality of porous arms defining a drainage geometry, FIG. 9E is adetailed view of a single arm of the embodiment of FIG. 9 D, FIG. 9 Fshows a embodiment of a drain device comprising a needle.

FIG. 10 illustrates a method for the concurrent removal of blood fromthe aneurysm site and filling medium injection into the fillingstructure.

FIGS. 11A-B are lateral and cross sectional views illustratingembodiments of an inflatable multi-lobe support member that allows forthe drainage of blood from the aneurysm site during inflation.

FIGS. 12A-B are lateral and cross sectional views illustratingembodiments of a multi-balloon support member that allows for thedrainage of blood from the aneurysm site during inflation.

FIGS. 13A-B illustrate the use of an embodiment of a multi balloonsupport member to allow the drainage of blood from the aneurysm siteduring inflation

FIG. 14A is a perspective view illustrating an embodiment of anexpandable stent support member that allows for the drainage of bloodfrom the aneurysm site during inflation in the non-expanded state.

FIG. 14B is a perspective view illustrating an embodiment of anexpandable stent support member that allows for the drainage of bloodfrom the aneurysm site during inflation in the expanded state.

FIG. 14C illustrates use of the expandable stent structure to allow forthe to allow the drainage of blood from the aneurysm site duringexpansion.

FIGS. 15A-C are perspective views illustrating embodiments of anexpandable basket support member that allows for the drainage of bloodfrom the aneurysm site during inflation. 15A is in the non-expandedstate, 15B is partially expanded and 15C is in the fully expanded state.

FIGS. 16A-B are perspective views illustrating embodiments of anotherexpandable support member that allows for the drainage of blood from theaneurysm site during inflation. 16A is in the non-expanded state and 16B is in the expanded state.

FIGS. 17A-C are perspective, lateral and cross sectional viewsillustrating embodiments of a coiled filling structure that allows forthe drainage of blood from the aneurysm site during filling.

FIG. 18 is a perspective view of a continuously coiled helical fillingstructure.

FIG. 19 is a perspective view of a continuously coiled filling structurehaving a FIG. 8 shape.

FIGS. 20A-C illustrate use of a continuously coiled filling structurefor repair of an arterial aneurysm.

FIGS. 21A-21C illustrate use of a pair or continuously coiled fillingstructures for repair of an arterial aneurysm near an arterialbifurcation.

FIGS. 22A-B are perspective and lateral views illustrating anembodiments of a inflatable support member having flared end portions.

FIG. 22C illustrates use of the flared support balloon to produce afilling structure blood flow lumen with flared end portions.

FIG. 23 illustrates an embodiment of the prosthesis system comprising afilling structure mounted over a delivery catheter in which the deliverycatheter includes a perfusion lumen and proximal and apertures for theperfusion of blood through the lumen during filling of the fillingstructure.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to FIGS. 1A-1D, an embodiment of a system 10 constructedin accordance with the principles of the present invention fordelivering a double-walled filling structure 12 to an aneurysm includesthe filling structure and a delivery catheter 14 having a supportstructure 16, at its distal end. Typically, support structure 16comprises an expandable element 16 such as expandable balloon. Thesupport structure can also comprise various mechanically expandablestructures, such mechanically expandable stents, basket devices andvarious mechanical structures having shape or spring memory. Thecatheter 14 will comprise a guidewire lumen 18, a balloon inflationlumen (not illustrated) or other structure for expanding otherexpandable components, and a filling tube 20 or other filling member 20for delivering a filling medium or material 23 to an internal space 22of the double-walled filling structure 12. The internal space 22 isdefined between an outer wall 24 and inner wall 26 of the fillingstructure. Upon inflation with the filling material or medium, the outerwall will expand radially outwardly, as shown in broken line, as willthe inner wall 26, also shown in broken line. Expansion of the innerwall 26 defines an internal lumen 28. The expandable balloon or otherstructure 16 will be expandable to support an inner surface of the lumen28, as also in broken line in FIG. 1A.

In many embodiments, system 10 includes a pressure monitoring 60 systemso as to be able to measure one or more pressures at the aneurysm sitebefore, during or after the filling of filling structure 12. System 60comprises a pressure sensing means 61 and a pressure monitoring means65. Sensing means 61 can comprise one or more pressure sensors 62 placedin the interior space 22 of structure 12 so as to measure the fillingpressure 69 within the structure, or placed on the external surface ofouter wall 24 so as to measure the pressure the blood pressure in 68 invessel space US, which is the space between the surface S of theaneurysms wall and outer wall 24. The sensor can comprise variouspressures sensor known in the art including various solid state sensors,MEMS-based sensors, optical sensors and other miniature pressure sensorsknown in the art. Also multiple sensors 62 can be placed on the interiorand exterior of the structure so as to produce a sensor array 62A. Thesensors can be coupled to pressure monitoring means by a cable C orother electrical coupling means known in the art.

Sensing means 60 can also include a pressure sensing member 63, whichcan include a guidewire, catheter or like structure. Sensing member 63can comprise a sensor tipped member such as a sensor tipped catheter, orit can have a lumen 64 for fluid communication with pressure monitoringmeans 65, such as an electronic pressure monitor which itself includes apressure sensor such as a strain gauge. Embodiments of the sensingmember having a lumen can also be configured to be used as a draindevice 80 discussed herein.

The sensing member can be configured to be both advanceable andsteerable either through the arterial vasculature or through a lumen ofdelivery catheter 14. In particular embodiments, it can be sized andhave mechanical properties to be advanced through delivery catheter 14into the interior space 22 of structure 12 so as to monitor the fillingpressure 69 in that space. It can also be sized and have mechanicalproperties to be advanced into the aneurysm site AS including vesselspace US from a vascular access point such as the femoral artery nearthe groin or the brachial artery near the arm pit. This allows themember to measure the blood pressure 68 in space US.

In many embodiments, system 60 can include two or more pressure sensingmembers 63 as is shown in FIG. 1C which can be positioned at differentlocations in or around the aneurysm site, AS. This provides thephysician with a more reliable indication of the pressure over theentire aneurysm site AS; it also provides for the ability to dodifferential pressure measurements over a particular length of the site(e.g. proximal to distal) as well differential measurements inside andoutside of the filling structure. For example, one sensing member couldbe positioned in space 22 within the filling structure and another invessel space US. It also allows the physician to spot check particularlocations in vessel space US to determine if there are any areas whichhave trapped blood and are rising too fast in pressure. In this way, thephysician can develop a pressure profile or barometric 3-dimensional mapof pressure over the entire aneurysm site (both inside and out of thefilling structure) and utilize that map to monitor and control thefilling process and entire aneurysm repair procedure.

In various embodiments, pressure monitoring means 65 can comprise agauge, a dedicated electronic pressure monitor, a modular monitorconfigured to be integrated with other medical monitoringinstrumentation, computer with pressure mentoring capability or likedevice. Typically the monitoring means will comprise an electronicpressure monitor having a display 66 for displaying a pressure waveform67 and/or a numeric readout. It can also be configured to have one ormore alarms to alert the medical staff when a pressure threshold hasbeen reached. The monitoring means can also be integral to or otherwisecoupled to a control system 70 discussed below for controlling thefilling rate and pressure of filling structure 12.

In various embodiments, one or more of the monitored pressures at siteAS can be used to control the filling process of structure 12 includingboth the flow rate of filling medium 23 and the pressure used to fillthe structure by a syringe pump or other fluid delivery means. This canaccomplished by the physician eyeballing the pressure and making manualadjustments to flow rate on a syringe pump. It many embodiments, it canbe accomplished by means of a control system 70 which can comprise acomputer or processor 71 coupled to pressure sensing means 60 and afluid delivery means 75. Computer 70 can include or be coupled to apressure monitoring means 65 which in turn are coupled to pressuresensing means 60. Computer 70 can receive input signals 75 frompressuring sensing means 60 and send output signals 76 to fluid deliverymeans 75 for the control of the flow rate and delivery pressure ofmedium 23 to filling structure 12. Fluid delivery means can include asyringe pump, peristaltic pump, metered pump or other medical pump knownin the art The computer include one or more modules or controlalgorithms 72 for controlling flow rate and pressure of fluid deliverymeans 75 responsive to input signal 75 from sensor means 60. Modules 72can include one or more P, PI, or PID or other control algorithms knownin the art. In many embodiments, modules 72 can be configured to utilizea threshold pressure, or rate of pressure change to control the fillingprocess. For example, the module can be configured to slow or stop thefilling rate when a monitored pressure reaches or approaches thethreshold. This threshold can be pre-set by the physician or can bedetermined through measurement and comparison to the patients bloodpressure as is explained below.

In addition to controlling the filling process, pressure monitoring,done either manually or through control system 70 can be utilized todetermine an endpoint for filling the filling structure. Similar to thecontrol of flow rate, the endpoint can be determined based upon reachingor approaching a pressure threshold either absolute or a rate of change.Pressure monitoring can be used to determine the endpoint out right, orin some cases can be used to titrate or fine tune endpoint determinationby coupling this information together with observation of the deployedsize of the filling structure and total volume of medium delivered.Computer 71 can be programmed to alert the physician when an endpoint isapproaching based on pressure measurement and then allow the physicianto fine tune the process. The computer can also be programmed to givethe physician a pressure range or window for making a manual endpointdecision with an ultimate shut off value. In this way the system affordsthe physician the ability to fine tune the endpoint while stillproviding a fail safe protection function to prevent the physician fromexceeding a pressure threshold which may cause dissection or otherdamage to the aneurysm wall.

In various embodiments, filling can also be controlled by means of avalve 40 coupled to filling structure 12 either directly or to fillingtube 20 as is shown in FIG. 2. In one embodiment, the valve can beconfigured as a mechanical pressure relief valve 40 r configured to openand relieve pressure from interior 22 when a threshold pressure has beenreached. In another embodiment the valve can be an electronicallycontrolled valve 40 e which either opens to relieve pressure within thefilling structure when the threshold pressure is reached or closes toprevent the influx of additional filling medium. In the former case, thevalve can be coupled to an exterior wall of the filling structure and inthe latter case it can be coupled to filling tube 20 or other fillingmember used to fill the filling structure. The electronic valve 40 e canbe controlled responsive to a pressure signal directly from a pressuresensor 62, or a signal 77 from control system 70.

Referring now to FIGS. 1C-E, in various embodiments, the patient bloodpressure can be utilized in determining a pressure threshold for bothcontrolling the filling process and determining an endpoint for filling.In one embodiment, sensing system 60 can be used to measure thepatient's blood pressure 68 at the aneurysm site AS, such as theirmaximum systolic pressure, before placement of filling structure 12 asis shown in FIG. 1C. This maximum value 68 m then becomes the thresholdvalue that is used for control of the filling process. Other values canalso be used such maximum diastolic pressure, or maximum time averagedpressure (e.g., over one minute). One or more filling structures canthen be deployed and filled as shown in FIG. 1D with a pressure sensingmember positioned in the interior 22 of the filling structure to monitorfilling pressure 69. Filling can be completed when the filling pressureremains at or slightly above maximum pressure 68 m, for example by 10%to 20%. This can also be corroborated by imaging observation to see ifthe filling structures are fully inflated and/or slightly oversized tosee that filling structures are completely filling in the aneurysm. In adifferent approach shown in FIG. 1E, filling can be completed based on ameasured maximum or other value of blood pressure in vessel space, US.This measurement can also be compared to the prior measure maximum value68 m without the filling structure in place.

Referring now to FIG. 2, the various internal and external surfaces maybe shaped, coated, treated, or otherwise modified to provide for anumber of particular features in accordance with the principles of thepresent invention. For example, the outer wall 24 may be shaped to haverings, stipples, or other surface features which are typically formedinto the material of the structure at the time of molding, vapordeposition, or other manufacturing process. The outer surface may alsobe coated with materials 28 which can be adhesives, drugs, activesubstances, fibers, flocking, foams, or a variety of other materials. Inmost cases, such surface features or modifications will be intended toenhance sealing or attachment of the outer wall 24 to the inner surfaceof the aneurysm being treated.

The inner surface 30 of the filling volume 22 may also be modified byproviding features, coatings, surface roughening, or a variety of othermodifications. The purpose of such internal features is typically toenhance adherence of the walls to the filling material or medium as themedium is cured or otherwise hardened. In some instances, materials maybe coated on all or a portion of the inside surface 30 to induce orcatalyze hardening of the filling material as it is being introduced.

The double-walled filling structure 12 will typically comprise at leastone valve 40 to permit the introduction of the filling material ormedium into the internal volume 22. As illustrated, the valve 40 may bea simple flap valve. Other more complex ball valves, and other one-wayvalve structures may be provided. In other instances, two-way valvestructures may be provided to permit both filling and selective emptyingof the internal volume 22. In other instances, the filling tube maycomprise a needle or other filling structure to pass through the valve40 to permit both filling and removal of filling medium. Valve 40 mayalso be configured as a mechanical pressure release valve 40 rconfigured to open and relieve pressure when the filling in space 22exceeds a preset threshold. Such pressure relieve valves 40 r can beplaced both in supply tube 20 and also in the external wall 24 of thefilling structures. When they open, such valves allow filling medium toexit the filling structure when placed in wall 24 or divert it fromentering in the first place when placed in supply tube 20. Valve 40 canalso be an electronically controlled valve 40 e configured to shut offin response to a signal from a pressure control system 70, or directlyfrom a pressure sensor 62 described herein so as to stop the inflow ofmedium 23 when the pressure in space 22 exceeds a threshold.

As illustrated in FIG. 2, the wall structure of the double-walledfilling structure may be a single layer, typically molded or otherwiseconventionally formed. The wall structures may also be more complex, forexample, as illustrated by FIGS. 3A-3C. FIG. 3A shows a multi-layeredwall comprising layers 42, 43 and 44. It will be appreciated that suchmultiple layer structure can provide for increased strength, punctureresistance, variations in compliance and/or flexibility, differences inresistance to degradation, and the like. As shown in FIG. 3B, a singlewall or multiple wall structure can be reinforced by braid, coils, orother metal or non-polymeric reinforcement layers or structures. Asshown in FIG. 3C, the external surface 24 of the wall may be coveredwith drugs, fibers, protrusions, holes, active agents or othersubstances for a variety of purposes.

Referring now to FIG. 4, the anatomy of an infrarenal abdominal aorticaneurysm comprises the thoracic aorta (TA) having renal arteries (RA) atits distal end above the iliac arteries (IA). The abdominal aorticaneurysm (AAA) typically forms between the renal arteries (RA) and theiliac arteries (IA) and may have regions of mural thrombus (T) overportions of its inner surface (S).

Referring to FIGS. 5A-5D, the treatment system 10 of FIG. 1 may beutilized to treat the complex geometry of the transmural abdominalaortic aneurysm (AAA) of FIG. 4 by first positioning the deliverycatheter 14 to place the double-walled filling structure 12 (in itsunfilled configuration) generally across the aneurysm from the region ofthe aorta beneath the renal arteries (RA) to a region over the iliacarteries (IA), as best seen in FIG. 5A. Usually, the delivery catheter14 will be introduced over a guidewire (GW) through a puncture in thepatient's groin accessing the iliac artery by the Seldinger technique.

After the double-walled filling structure 12 is properly positioned, ahardenable inflation medium is introduced into the internal space 22.Filling of the inner space 22 then expands the outer wall 24 of thestructure outwardly so that it conforms to the inner surface (S) of theaneurysmal space.

Before, during, or after filling of the double-walled filling structure12 with inflation medium, as illustrated in FIG. 5B, the balloon 16 orother expansible structure will also be inflated or expanded to open thetubular lumen defined by the interior of the inner wall 26. In apreferred embodiment, the balloon 16 will be generally non-compliant,typically having a maximum diameter of width which is at or slightlylarger than the desired tubular lumen diameter or width through thedeployed filling structure 12. The filling structure 12, in contrast,will be partially or completely formed from a generally compliantmaterial, thus allowing the non-compliant balloon or other expansiblestructure 16 to fully open the tubular lumen and conform to the ends ofthe lumens to the aorta and iliac walls, as illustrated in FIG. 5C. Alower or proximal end 50 of the tubular lumen will be flared to a largerdiameter so that it can accommodate the openings of both the iliacarteries (IA) as illustrated. Thus, it will be preferred to utilize afilling structure 12 geometry which has been chosen or fabricated tomatch the particular patient geometry being treated. It will also bepreferable to use a balloon 16 or other expansible structure which willbe shaped to preferentially open the lower proximal end 50 of thetubular lumen to a larger diameter than the upper or distal end 52.

After the filling material has been introduced to the filling structure12, typically through the filling tube 20, the fluid filling materialcan be cured or otherwise hardened to provide for the permanent implanthaving a generally fixed structure which will remain in place in theparticular aneurysmal geometry. Pressure monitoring can be performedduring all or a portion of the hardening period and can be used todetermine an amount or endpoint of hardening. Methods for curing orhardening the filling material will depend on the nature of the fillingmaterial. For example, certain polymers may be cured by the applicationof energy, such as heat energy or ultraviolet light. Heat energy can beapplied using various energy delivery means including RF, ultrasonic andinfrared delivery means. Other polymers may be cured when exposed tobody temperature, oxygen, or other conditions which cause polymerizationof the fluid filling material. Still others may be mixed immediatelyprior to use and simply cured after a fixed time, typically minutes.Often, after the filling material has been hardened, the deliverycatheter 12 may be removed and the filling structure left in place asthe completed prosthetic implant. The pressure sensing and/or draindevice (discussed herein) can also be removed at this time or left inplace for a selected period. In still other embodiments, the fillingmedium need not be hardenable/curable but rather has rheologicalproperties configured to mimic blood or native tissue. Such mediums caninclude various silicone solutions known in the art.

In other cases, however, it may be desirable to further position certainseals, anchors, stents, or other additional prosthetic components ateither the proximal end 52 or distal end 50 of the graft. As illustratedin FIG. 5D, for example, a stent-like structure may be planted in theupper proximal opening 52 of the tubular lumen of the filling structure12 in order to help anchor the structure, help prevent intrusion ofblood into the region between the outer wall 24 and inner surface (S) ofthe aneurysm, and to generally improve the transition from the aortainto the tubular lumen. The sealing or anchoring structure may simplycomprise a stent-like component, preferably having a port or otheraccess route to allow blood flow into the covered renal arteries (ifany). Alternatively, the anchor structure could be another inflatableunit, such as the anchor described in co-pending, commonly ownedapplication Ser. No. 10/668,901 (published as US2004/0116997A1), thefull disclosure of which is incorporated herein by reference.

In a particular and preferred aspect of the present invention, a pair ofdouble-walled filling structures will be used to treat infrarenalabdominal aortic aneurysms, instead of only a single filling structureas illustrated in FIGS. 5A-5C. A system comprising such a pair offilling structures is illustrated in FIG. 6 which includes a firstfilling structure 112 and a second filling structure 212. Each of thefilling structures 112 and 212 are mounted on delivery catheters 114 and214, respectively. The components of the filling structures 112 and 212and delivery catheters 114 and 214 are generally the same as thosedescribed previously with respect to the single filling structure system10 of FIG. 1. Corresponding parts of each of the fillings systems 112and 212 will be given identical numbers with either the 100 base numberor 200 base number. A principal difference between the fillingstructures 112 and 212, on the one hand, and the filling structure 12 ofFIG. 1 is that the pair of filling structures will generally haveasymmetric configurations which are meant to be positioned adjacent toeach other within the aneurysmal space and to in combination fill thatspace, as will be described with specific reference to FIG. 7A-7F below.

In treating an infrarenal abdominal aortic aneurysm using the pair offilling structures 112 and 212 illustrated in FIG. 6, a pair ofguidewires (GW) will first be introduced, one from each of the iliacarteries (IA). As illustrated in FIG. 7A, the first delivery catheter114 will then be positioned over one of the guidewires to position thedouble-walled filling structure 112 across the aortic aneurysm (AAA), asillustrated in FIG. 7B. The second delivery catheter 214 is thendelivered over the other guidewire (GW) to position the second fillingstructure 212 adjacent to the first structure 112 within the aneurysm(AAA), as illustrated in FIG. 7C. Typically, one of the fillingstructures and associated balloons will be expanded first, followed bythe other of the filling structures and balloon, as illustrated in FIG.7D where the filling structure 112 and balloon 116 are inflated to fillgenerally half of the aneurysmal volume, as illustrated in FIG. 7D.Filling can generally be carried out as described above with the onefilling structure embodiment, except of course that the fillingstructure 112 will be expanded to occupy only about one-half of theaneurysmal volume. After the first filling structure 112 has beenfilled, the second filling structure 212 may be filled, as illustratedin FIG. 7E. The upper ends of the balloons 116 and 216 will conform thetubular lumens of the filling structures against the walls of the aortaas well as against each other, while the lower ends of the balloons 116and 216 will conform the tubular lumens into the respective iliacarteries (IA).

After filling the filling structures 112 and 212 as illustrated in FIG.7E, the filling materials or medium will be cured or otherwise hardened,and the delivery catheters 114 and 214 removed, respectively. Thehardened filling structures will then provide a pair of tubular lumensopening from the aorta beneath the beneath the renal arteries to theright and left iliac arteries, as shown in broken line in FIG. 7. Theability of the filling structures 112 and 212 to conform to the innersurface (S) of the aneurysm, as shown in FIG. 7F, helps to assure thatthe structures will remain immobilized within the aneurysm with littleor no migration. Immobilization of the filling structures 112 and 114may be further enhanced by providing any of the surface featuresdescribed above in connection with the embodiments of FIG. 2.Optionally, and not illustrated, anchoring or sealing structures couldbe provided in either of the upper or proximal openings of the tubularlumens into the aorta or from either of the distal or lower openingsinto the respective iliac arteries.

Referring now to FIGS. 8A-D, in various embodiments system 10 caninclude a drain device 80. Drain device 80 provides for the draining ofblood and other fluid from the vessel space (VS) between the aneurysmswall (AW) and the external surface S of the filling structure 12. Byremoving blood or other fluid which may be trapped in space VS duringfilling of the filling structure draining serves to reduce the pressureforces exerted against the aneurysm wall by the expansion of filingstructure and thus reduce the associated risk of aneurysm dissection orrupture. The device can be configured to provide for passive drainingfrom the pressure exerted by blood BD in space VS (as is shown in FIG.8B) or active draining from a vacuum source 87 such as a syringe (as isshown in FIGS. 8C and 8D). The device can be configured to be temporallyor permanently left in place at site AS

In many embodiments, the drain device will comprise a flexible memberhaving an inflow portion 82 to provide for the inflow of blood BD otherfluid and a outflow portion 83 to provide for the outflow either intoadjoining vessels or external to the patient's body. As shown in FIGS.9A and 9B, inflow portion 82 can comprise a porous portion 84 which canhave a plurality of apertures 85 provide for inflow of fluid frommultiple locations over portion 82 and also provides redundancy shouldone or more of the apertures become blocked with thrombus or othermatter. In one embodiment shown in FIG. 9C, inflow portion 81 will behelically or otherwise wrapped around the circumference of structure 12so as to define a drainage volume or geometry 88. Various drainagegeometries such as spherical, cylindrical etc., can be defined based onthe positioning of the porous portion around the filling structures andthe shape of the filling structure. Also the pattern 85 p and shape ofapertures 85 over geometry 88 can be configured to optimize draining fora particular orientation of the drain. For example, in cases ofdownstream passive draining, the more proximal section of the porousportions can have a greater aperture density and/or larger diameterapertures. These and related configurations of the porous portionprovides for drainage of blood BD from multiple locations within spaceUS so as to produce more uniform draining and minimize the likelihood ofblood BD or other fluid from becoming trapped within a particularlocation within space.

In another embodiment shown in FIGS. 9D and 9E the inflow portion 82 cancomprise a series of arms 84A that are longitudinally or otherwisedistributed around the circumference of structure 12. All or a portionof each arm can have a porous portion 84. Arms 84A can also serve todefine a drainage volume or geometry 88. The inflow portion for both theembodiments of FIGS. 9D and 9E can be coupled to structure 12 usingvarious joining methods known in the art including adhesive orultrasonic welding, it can also be held in place by tension and/orfrictional forces. The inflow portion of either embodiment can beconfigured to readily detached from structure 12 using e.g., a low forceadhesive to allow the drain to be removed through use of a laparoscopicinstrument. They also need not be attached to the structure but canexist as separate structure which can be attached to deliver catheter 14or can be otherwise removed using a guidewire, laparoscopic instrumentor other means. In various embodiments this can be facilitated throughthe use of retrieval element such as a loop, hook or like structure (notshown) attached to a portion of the drain device to allow it beretrieved from either an upstream or down stream approach.

In an embodiment shown in FIG. 9F drain device 80 can comprise a needle89 which is configured to be inserted into vessel space US by alaparoscopic approach or other method. A vacuum can then be pulled onthe needle using a syringe or other vacuum source 87. This method allowsthe doctor to easily and quickly remove a desired volume of bloodconcurrent to the delivery of filling medium to structure 12. The doctorcan make the withdrawal manually while monitoring pressure duringfilling so as to stay below a select pressure (e.g., 20% above thepatients blood pressure). Also the withdrawal can be done automaticallyusing a syringe pump. The rate can be adjusted manually and the pump canbe coupled to a computer/processor having an algorithm that controls thewithdrawal rate based on monitored pressure(s) at site AS.

Referring now to FIG. 10, in a variation of the above embodiment, system10 can be configured to allow for a substantially equal rate of bloodremoval from site AS as the flow rate of filling medium 23 injected intothe filling structure 12 (and hence to the total volumes as well). Thewithdrawal and injection can be done simultaneously or nearsimultaneously and at substantially the same rate using a dual actionsyringe pump or other concurrent injection and withdrawal means 75 knownin the art. Pressures can be monitored continuously during thisprocedure and the withdrawal rate and/or injection rate can be adjustedaccordingly to maintain pressure below a threshold or other set point.

Outflow portion 83 will typically comprise a tube portion 86 (alsocalled tube 86) that can be configured to extended proximally ordistally from site AS into the lumen LN of the native vessels NVadjoining site AS. The tube can be extended various lengths into thevessels NV, e.g., several millimeters to several centimeters. In someembodiments where draining is done passively (as is discussed herein),the tube 86 will be positioned distally or downstream from site AS so toallow passive draining of blood due to the hydrostatic pressure forcesexerted by blood or other fluid in space AS. In other embodiments wheredraining is done actively (e.g., from the use of a vacuum), tube 86 canbe positioned proximally relative to site AS. For embodiments where thedevice is left in at site AS for post implant draining, the tube ispreferably configured to only slightly extend into lumen LN of thenative vessel and is configured to be located close to be close to lumenwall (e.g., several millimeters) to minimize contact area with flowingblood. The tube portion can also be sized to be connected to asubcutaneous or a cutaneous access device/fluidic connector or reservoir(not shown) to allow for cutaneous access and removal of blood.

Tube portion 86 can also be configured to be detachable from theremainder of the drain device by means of a guidewire, catheter or otherminimally invasive method. This allows the physician to remove the tubeportion at a selected time period post implant (e.g., two weeks) atwhich time it is no longer needed. Detachability can be achieved throughthe use of a reliable joint known in the art or a low force adhesive.Tube portion 86 can also include a retrieval element discussed herein.

In still other embodiments, tube portion 86 may be sized to extend allthe way outside of the patients body through a vascular access site suchas at the groin. This latter embodiment allows for the draining of bloodand fluid both passively and actively by the application of vacuum. Itcan also be configured to be fluidly coupled to a pressure sensingmember 65 so as to allow the draining of blood through the pressuresensing member.

In various embodiments, drain device 80 can be constructed from variousnon-thrombogenic biomaterials known in the art such as silicone,polyurethane and the like so as to maintain patentcy of both the inflowand the outflow portions. Also, all or a portion of the drain can havevarious coatings, for example, non-thrombogenic coatings such as aheparin based coating to provide additional thrombogenic protection forvarious periods of use. In preferred embodiments it can be constructedfrom expanded PTFE. Also, all or a portion of the drain can also beconstructed from re-absorbable biomaterials known in the art so as toprovide a drain function for a selected time period before beingreabsorbed by the body. Also, the tube portion of the drain can beattached with a low force adhesive or otherwise treated to be detachableusing minimally invasive methods. For embodiment employing a needledevice, the needle can be fabricated from 304V or other stainless steelas well as superelastic materials such as NITINOL. It can also befabricated from various flexible polymers known in the art. The needleand the other embodiments of the drain device can also include variousfittings such as a Touhy Borst fitting or valve for connection to vacuumsources, pumps, pressure lines and the like.

In other approaches for draining blood from the vessel space US, theballoon support member or other mechanical support member can be shapedso as to not form a seal with the wall of the aneurysm or adjoiningartery when they are in an expanded state. This allows blood to flowaround the balloon/expansion device desirably both at the proximal anddistal end of the device. Such embodiment also allows any blood locatedin vessel space US to flow out or be squeegeed out from the aneurysmsite as the filling structure is expanded. Referring now to FIGS.11A-11B, in specific embodiments, the balloon 16 can comprise a lobeshaped balloon 16 l have a multi-lobed cross sectional profile 16 lpwhich allows blood to flow in the valleys 17V between the lobes 17 whilepeaks 17P of the lobes 17 provide support to maintain the tubular shapeof the inner lumen 12 l of filling member 12. Valley 17 p can also beconfigured to allow for the passage of a pressure sensing member 63 froma proximal to a distal end of the balloon. Balloon 16 l can have aselectable number of lobes 17, for example, between three and five lobesdepending the upon size of lumen 12 l and the desired amount of bloodflow. In one embodiment the balloon can have a three lobe profile 16 lp.

Referring now to FIGS. 12A-13B, other embodiments a balloon that allowsfor blood flow through lumen 12 l, can comprise a multi-balloon member16 mb made of two or more individual balloons 16 that are joinedtogether or share a common wall, for example, a three balloon member.These embodiments are configured to allow for blood flow in the spaces16 s between the balloons when they are inflated. Such embodiments canhave a multi-spherical cross-sectional profile 16 sp. In a preferredembodiment shown in FIGS. 12A and 12B, a multi-balloon support member 16mb can comprise three balloons and thus have a tri-spherical crosssectional profile 16 sp. Use of such of an embodiment of a multi-balloonsupport member is illustrated in FIGS. 13A-B which show how blood canflow through the balloon space 16 s and thus allow for both flow throughlumen 12 l and drainage of blood from space US when the balloon areinflated and the filling structure is being filled.

Referring now to FIGS. 14A-C, another embodiment for a support memberthat allows blood through lumen 12 l when in the expanded state caninclude and expandable shape memory stent 16 t comprising a plurality offlexible splines 19 that form a scaffolding structure 19 s that is ableto support lumen 12. The stent can have a non-deployed state shown inFIG. 14A and an expanded or deployed state shown in FIG. 14B. The stentcan be fabricated from various superelastic shape memory materials knownin the art such as nickel titanium alloys. In a preferred embodiment,the stent is fabricated from NITINOL. The stent may also be coated withvarious non-thrombogenic coatings, including eluting coatings known inthe art. Stent 16 t can be put into the expanded state by theapplication of either tension or compression from delivery catheter 14or guidewire GW or another pull wire not shown. FIG. 14C illustrates howthe scaffolding supports lumen 12 l and how blood is able to readilyflow through the stent when it is put into the expanded state.

Another embodiment of an expandable mechanical support structure thatallows blood flow is shown FIGS. 15A-15C. This structure is similar tostent 16 but comprises a basket like structure 16 b that also isfabricated from a plurality of splines 19 that have an outwardly curvedspring memory shape which they assume when they are released into theexpanded state. The splines desirably have sufficient spring memory tohold lumen 12 l open. Similar to stent 16 t, the basket structure can beput into the expanded state through the application of tension orcompression from guidewire GW or catheter 14. The splines can also beheld in the contracted state through a series of ring constraints 19 r.Alternatively the splines need not have an outwardly bowed spring memorybut rather can be held in that position through the application oftension or compression from guidewire GW or catheter 14.

Yet another embodiment of an expandable mechanical support structurethat allows blood flow is shown by FIGS. 16A-B. This embodimentcomprises a mechanically expandable support structure 16 having aplurality of flexible spring arms members 21 that can be pulled into anexpanded state by a series of connected pull wires 21 w. Pull wires 21 wcan be positioned in guidewire lumen 18 or another lumen of catheter 14and can be coupled to a common actuator (not shown) to pull all of theman equal amount at the same time. The actuator can have a lockingfeature to lock the arm members in the expanded state and also can beindexed for a selectable amount of outward radial expansion of the armmembers so as to define a diameter 12D between opposing arm members forsupporting lumen 12 l. There can also be several groups of arms 21 gmembers spaced longitudinally along catheter 14 to provide several ringsof radial support 21 for supporting lumen 12 l. Also, there can bepartially radially constrained/supported by a ring structure 21 rspositioned on catheter 14. Desirably, arm members 21 have sufficientspring memory in the straightened state such that they will resume thisshape when released by pull wires 21 w. Arm members 21 can be fabricatedfrom various spring and shape memory metals known in the art as well asvarious flexible polymers known in the art. All or a portion of the armmembers can be coated with a biomaterial coating includingnon-thrombogenic coating. Desirable the arm member tips 21 t areconfigured to be atraumatic and can be either coated, smoothed or caped.They can also be pre-shaped to be either straight or curved and can havea number or radio-opaque or echogenic markers positioned along theirlengths.

In other embodiments, filling member 12 can be configured so as not toneed support during filling/inflation and also during the perfusion ofblood through lumen 12 l during filling. Referring now to FIGS. 17A-18B,one embodiment of such a filling member comprise a coiled structure 12 cthat has an open central lumen 12 l for blood flow which does not needsupport during filling. Specifically the coiled structure has sufficientradial strength that it does not need radial support similar to maintainits shape when inflated, similar to the mechanics of an inner tube. Inone embodiment, the coiled structure can comprise a series of individualinflatable coils 12 ic having an inner tube like structure that arejoined and fluidically coupled to one another to allow simultaneousfilling/inflation as is shown FIG. 17B.

In another embodiment shown in FIG. 18, the coiled structure 12 c cancomprise a continuously coiled structure 12 cc that has a helical shape12 h when unconstrained. It can then be wrapped or packed aroundcatheter 14 to assume a substantially cylindrical coiled shape whendeployed in vivo. This structure can also be deployed from catheter 14into an aneurysm site in an extruded like manner using an overtube orguiding catheter. In another embodiment shown in FIG. 19, structure 12can have a “figure eight shape” 12 fe which can be configured fortreating aneurysm at or near a vessel bifurcation. Various embodimentsof coiled structure 12 c can be fabricated from various biocompatibleelastomers known in the art including silicone and polyurethane andco-polymers thereof. They can also be internally supported by braids,struts or other support element to help maintain the patentcy of theircentral lumen.

Referring now to FIG. 20A-20C, a method of using a coiled fillingstructure 12 c is illustrated. The structure can be position in thedesired site AS, using delivery catheter 14. Then coiled structure 12 cis filled/inflated with filling medium 23, without the need for asupport structure 16. However, one can be used if so desired by thephysician. The structure can be filled/inflated in such a manner as tosqueeze out blood from space US in a piston like manner. That is, aseach individual coils of the structure becomes inflated it push bloodfrom space US down the vessel in the direction of inflation DI (e.g.,proximal in the embodiment shown) until all of the coils are inflatedand all of the blood is forced out from space US. Each individual coil12 c acts as fluidic seal 12 fs which prevents blood from flowingbackward against the direction of inflation DI, thus forces theremaining blood in space US to travel in the path of least fluidicresistance which is in the direction of inflation. In use, suchembodiments minimize the likelihood of blood becoming trapped in spaceUS and also excessive pressure from being exerted against the aneurysmwall thus minimizing the risk of dissection. Similar to other methodembodiments discussed herein, pressure monitoring can be done throughoutthe filling and deployment process to control filling, determineendpoint and further reduce the risk of over-pressurization.

FIGS. 21A-C illustrate a variation of the method describe above adaptedfor used with an aneurysm near a vessel bifurcation. In theseembodiments a first and second coiled filling structure 112 c and 212 care used. Typically each structure will be positioned and then filledsequentially as is shown in FIGS. 21B-C though the physician can electto do simultaneous or otherwise concurrent fillings. In either case,pressure monitoring can be done throughout the procedure as describedabove to both control the filling process and determine endpoint.

Referring now to FIGS. 22A-22C, in some embodiments, the balloon supportmember 16 can have a dog bone 16 db or like shape (e.g., a cassini oval)such that the proximal and distal end portions 16 p and 16 d of theballoon have an outwardly flared shape 16 f or otherwise has a largerdiameter than the balloon central portion 16 c. One or both of the endportions 16 p and 16 d of the inflated balloon can extend at leastpartially out of the filling structure 12 into the native vessel lumenLN. This configuration serves to shape the lumen 12 l of the hardenedfilling structure such that the proximal and distal ends of the formedlumen 121 p and 121 d have an outwardly flared shape 12 f (relative tothe central portion 121 c) which roughly corresponds to flared shape 16f This flared shape 12 f serves to provide a smooth transition 12 t indiameter from the native vessel lumen NL to the formed lumen 12 l ofstructure 12 and in particular, minimizes the surface of the area of theformed lumen that is normal to the direction of blood flow BD throughthe artery. This later configuration serves to minimize an amount ofsheer stress on the formed and adjacent native lumens as well as reducean amount of retrograde flow and turbulence in vessel regions within andadjacent the prosthesis. These fluid dynamic factors in turn serve toreduce the likelihood of the formation of stenosis in the region of theprosthetic.

Referring now to FIG. 23, in other embodiments, perfusion duringinflation of the balloon support member can also be achieved by the useof a perfusion lumen 14 l with proximal and distal apertures 14 ap and14 ad for the inflow and outflow of blood. The proximal and distalapertures 14 ap and 14 ad are desirably positioned on the deliverycatheter so as to allow blood to enter the proximal apertures, flowthrough the delivery catheter lumen and exist the distal aperturesand/or distal end of the lumen 14 le when the balloon support 16 isinflated before, during or after filling of filling structure 12.Perfusion can be enhanced through the use of pressure monitoring toposition the inflow and outflow apertures in areas with greatest bloodflow and/or pressure gradient.

CONCLUSIONS

The foregoing description of various embodiments of the invention hasbeen presented for purposes of illustration and description. It is notintended to limit the invention to the precise forms disclosed. Manymodifications, variations and refinements will be apparent topractitioners skilled in the art. For example, embodiments of theaneurysm repair system, and prostheses can be adapted to be utilized inthe thoracic region of the aorta or other vasculatures of the bodyincluding, without limitation, the cerebral vasculature and the femoraland popliteal vasculatures. Also, embodiments of dual filling structuresystem can be adapted to treat aneurysms at or near any bifurcation inthe arterial vasculature.

Elements, characteristics, or acts from one embodiment can be readilyrecombined or substituted with one or more elements, characteristics oracts from other embodiments to form numerous additional embodimentswithin the scope of the invention. Moreover, elements that are shown ordescribed as being combined with other elements, can, in variousembodiments, exist as stand alone elements. Hence, the scope of thepresent invention is not limited to the specifics of the describedembodiments, but is instead limited solely by the appended claims.

What is claimed is:
 1. A method for treating an aneurysm in a patient,the method comprising: positioning at least one double-walled fillingstructure across the aneurysm; filling the at least one fillingstructure with a filling medium so that an outer wall conforms to theinside of the aneurysm and an inner wall forms a generally tubular lumento provide for blood flow across the aneurysm, wherein the blood flowdirectly contacts a surface of the inner wall, and wherein the at leastone filling structure substantially fills the aneurysm when filled withthe filling medium; supporting the tubular lumen with a supportstructure during filling and/or after the filling of the at least onedouble-walled filling structure with the filling medium; and monitoringaneurysm repair by monitoring at least a first pressure measured at theinterior of the at least one filling structure with a pressuremonitoring system during filling and/or after filling of the at leastone filling structure; and wherein monitoring aneurysm repair furthercomprises monitoring a second pressure between an outer surface of theat least one filling structure and a wall of the aneurysm with thepressure monitoring system during filling and/or after filling of the atleast one filling structure.
 2. The method of claim 1, wherein the firstpressure comprises a filling pressure of the filling medium duringfilling of the at least one filling structure.
 3. The method of claim 2,further comprising: determining an increase of the pressure differentialbetween the first pressure and the second pressure, with the pressuremonitoring system.
 4. The method of claim 3, further comprising:determining an end point of filling of the at least one fillingstructure with the filling medium based on the pressure increase of themonitored filling pressure.
 5. The method of claim 2, furthercomprising: controlling a flow rate of the filling medium during fillingof the at least one filling structure based on the monitored fillingpressure.
 6. The method of claim 1, further comprising: controllingfilling of the at least one filling structure based on the first andsecond monitored pressure.
 7. The method of claim 1, wherein the secondpressure comprises a pressure between an outer surface of the at leastone filling structure and a wall of the aneurysm.
 8. The method of claim1, further comprising: positioning a pressure monitoring catheter,guidewire or pressure sensing member placed at an aneurysm site betweenthe filling structure and a wall of theaneurysm.
 9. The method of claim1, further comprising: controlling filling of the at least one fillingstructure based on the first pressure.
 10. The method of claim 9,wherein controlling filling is performed automatically with a meteredpump coupled with a computerized control system.
 11. The method of claim1, further comprising: determining an end point of filling of the atleast one filling structure based on the first pressure.
 12. The methodof claim 11, wherein the end point of filling is determined in responseto the first pressure reaching a selected threshold pressurecorresponding to an increased likelihood of dissection of the aneurysm.13. The method of claim 12, wherein the selected threshold pressure isdetermined based on a size and shape of the particular aneurysm, apatient blood pressure, a wall thickness of the aneurysm, and/or adimensional, mechanical or morphological characteristic of the aneurysm.14. The method of claim 1, wherein the filling medium comprises any of:a curable two-part material, a polymer, an epoxy, and a liquid of stableform.
 15. The method of claim 1, wherein the filling medium comprises acurable medium comprising any of: a liquid, a gel, a foam, and a slurry.16. A system for treating an aneurysm comprising: at least onedouble-walled filling structure that is implantable across the aneurysm,the double-walled filling structure having an inner wall and an outerwall that are conformable so that when filled with a filling medium, theouter wall conforms to an inside of the aneurysm and the inner wallconforms forms a generally tubular lumen to provide for blood flowacross the aneurysm; an expandable support member disposed within the atleast one double-walled filling structure so as to support the generallytubular lumen during filling and/or after filling of the at least onedouble-walled filling structure; and a pressure monitoring system havingone or more pressure sensors in fluid communication with an interior ofthe at least one double-walled filling structure and one or morepressure sensors disposed between an exterior of the at least onedouble-walled filling structure and inside surface of the aneurysm. 17.The system of claim 16, further comprising: a tube configured to deliverthe filling medium into the at least one double-walled fillingstructure, wherein the tube is coupled to a controller communicativelycoupled with an output of the one or more pressure sensors, thecontroller configured to control one or both of a flow rate and afilling pressure based on the output from the one or more pressuresensors.